Weekly SARS-CoV-2 screening of asymptomatic kindergarten to grade 12 students and staff helps inform strategies for safer in-person learning.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in K-12 schools was rare during in 2020-2021; few studies included Centers for Disease Control and Prevention (CDC)-recommended screening of asymptomatic individuals. We conduct a prospective observational study of SARS-CoV-2 screening in a mid-sized suburban public school district to evaluate the incidence of asymptomatic coronavirus disease 2019 (COVID-19), document frequency of in-school transmission, and characterize barriers and facilitators to asymptomatic screening in schools. Staff and students undergo weekly pooled testing using home-collected saliva samples. Identification of >1 case in a school prompts investigation for in-school transmission and enhancement of safety strategies. With layered mitigation measures, in-school transmission even before student or staff vaccination is rare. Screening identifies a single cluster with in-school staff-to-staff transmission, informing decisions about in-person learning. The proportion of survey respondents self-reporting comfort with in-person learning before versus after implementation of screening increases. Costs exceed $260,000 for assays alone; staff and volunteers spend 135-145 h per week implementing screening.

Congenital anerythremic erythroleukemia presenting as hepatic failure.

We report an atypical case of congenital erythroleukemia in a child born with hepatosplenomegaly and abnormal liver tests. The initial peripheral blood cell count showed anemia and hyperleukocytosis with erythroblastosis that disappeared 1 week later. During the next 5 weeks, no blasts were found in the blood, and less than 5% were found on 2 successive bone marrow aspirates. The infant died of hepatic failure. The suspected diagnosis on a premortem liver biopsy was confirmed by an autopsy that showed a blastic infiltration in many organs. These cells expressed only erythroid markers glycophorin A and C. Rearrangement of the myeloid lymphoid leukemia gene was not found by fluorescence in situ hybridization. The main differential diagnoses include metabolic diseases, Langerhans histiocytosis, Pepper syndrome, transient myeloproliferative disorder, and leukemoid reactions. Although some of these can be excluded by the pathologist, others require a multidisciplinary confrontation: clinical, biologic, genetic, and pathologic examinations.